On many battlefields, well-known target signatures are distorted by real-world effects, such as various and varying environmental conditions. Further, new, heretofore-unknown targets emerge that need to be defined. As a consequence, updates of a target acquisition or automatic target recognition (ATR) knowledge base are and continue to be a necessity for autonomous precision strike weapons. Such autonomous precision strike weapons utilize all possible target sensing means except direct laser designation of the targets.
ATR systems that use some type of pattern recognition need some form of knowledge or training database resident in the systems for proper operation. Since the performance of any ATR system is limited by these training data and often even known targets are obscured by camouflage and other means, most real-world applications require some real-time updates (i.e. retraining) of the target knowledge database. This requirement also holds true for any new mobile or fixed targets. This “real-time” retraining is referred to as rapid retraining or rapid target update.
In an ATR system, the typically required information for the pattern recognizer consists of target and background clutter signatures in the electromagnetic band of interest. The robustness of ATR performance is usually quantified by correct classification of targets in some form, such as recognition or identification and false alarms defined as either clutter or misclassifications. The best ATR for any specific system application can be selected from known algorithms that are amenable to rapid retraining and also appropriate for the timeline for the specific application at hand. To maintain the ATR robustness through rapid target updating, however, the ATR must have the flexibility to be reconfigured in response to the target scene information provided by the surveillance means. Part of this updating process includes establishing metrics of the clutter in the target scene so that the criteria on ATR performance can be established for the specific target environment.
In general, multiple simultaneous weapon engagements are desired to eliminate multiple targets in a very short period of time. The rapid retraining of multiple weapons is restricted by the limitations of available and compatible sensors.